Hi Tony. For those desired results I think you will be happy with the 891's and here's why. I originally had 890's in my 4Runner because I was very worried about having too stiff of a ride quality with 891's (I shouldn't have been). That was before I built my RB shelf mod, added the rear bumper and tire carrier, and a bit of trail gear constantly kept in the rig. Once all that was done the 890's just gave up and I had back the notorious sag. I swapped in 891's and was extremely happy for a couple of months. But then the 891's started sagging, albeit every so slightly. The ride quality is just fine.
I believe with the weight you are talking about these will give you the desired result you are looking for at 2-2.5" over time. I am also making an assumption that you will realize the weight adds up quicker than you think and the estimated couple of hundred pounds you are talking about will actually end up being more. FWIW IMHO YMMV.
Ash, I really appreciate you taking the time to share as you did. Confirmation is certainly a good feeling...
I saw a photo of your shelf mod a few days back and it looks great! How much weight, about, does it add, along with your roll hoop and equipment you have back there?
As you know, I have a trailer and I plan to outfit that for storage and camping ventures, along with a rack for both THD runs (plywood, drywall, etc) and a RTT. The trailer is 4'x6' and will carry of all our camping gear. It will be packed and always ready to go...
As for added weight in the rear of the 4Runner, here's what I see ultimately for non-camping treks, not including little ones in the back seat as that is not exactly the rear...
- Savage rear bumper with carrier (spare and jack)
This aftermkt rear bumper itself will add zero weight compared to what I have now (factory bumper with tow hitch). I will get the carrier though, and that is 45 lbs. The spare will actually be a little lighter given the wheels of choice, so no addtional weight there. About 30 lbs for a hi lift jack? If so, that's 75 lbs addtional weight.
- 18 gallon Ford aux tank
At 6 lbs per gallon of fuel, plus the tank and necessary hardware, figure on the max weight (when full), at 150 lbs.
- Cargo area gear
When not taking the trailer, maybe a 100 pounds in the back, like for our Tahoe trips. Of some note, I ditched (sold) the cargo privacy screen, and that thing weighs 8 pounds.
- Roof rack
The aluminum Rocky Mountain Antero Extension "half rack" added just 15 pounds, not all of that in the rear...
++++++
Once I have the aftermkt bumper with carrier, the aux tank in the factory spare location and full of gas, family gear in the cargo area, I'm looking at a 325 pounds. Given the dynamic weight of the fuel, 325 looks to be the max.